MEDIUM
Earn 100

Out of 800 boys in a school, 224 played cricket, 240 played hockey and 336 played basketball. Of the total, 64 played both basketball and hockey; 80 played cricket and basketball and 40 played cricket and hockey; 24 played all the three games. The number of boys who did not play any game is

50% studentsanswered this correctly

Important Questions on Sets

MEDIUM

If A={1,2,3,4,5} and B={2,4,6}, then A-B=

EASY
If AB, then AΔB is equal to
HARD
Let A and B be finite sets such that n(A-B)=18,n(AB)=25 and n(AB)=70. Then n(B) is equal to
HARD

Let i=150Xi=i=1nYi=T, where each Xi contains 10 elements and each Yi contains 5 elements. If each element of the set T is an element of exactly 20 of sets Xi's and exactly 6 of sets Yi's then n is equal to :

EASY
Let X=nN:1n50. If A=nX: n is a multiple of 2 and B=nX: n is a multiple of 7, then the number of elements in the smallest subset of X, containing both A and B, is.
EASY
A survey shows that 73% of the persons working in an office like coffee, whereas 65% like tea. If x denotes the percentage of them, who like both coffee and tea, then x cannot be:
HARD
In a group of 100 persons, 80 people can speak Malayalam and 60 can speak English. Then the number of people who speak English only is
EASY
Let A and B be two sets such that AX=BX=ϕ and AX=BX for same set X. Then,
EASY
If A={x|xN,x is a prime number less than 12} and B={x|xNx is factor of 10}, then AB=
MEDIUM
If A=xR:x<2 and B=xR:x-23; then
MEDIUM
Consider the two sets:
A={mR: both the roots of x2-(m+1)x+m+4=0 are real } and B=[-3,5)
Which of the following is not true?
MEDIUM
In a class of 140 students numbered 1 to140 , all even numbered students opted Mathematics course, those whose number is divisible by 3 opted Physics course and those whose number is divisible by 5 opted Chemistry course. Then the number of students who did not opt for any of the three courses is:
EASY
If nA=3, nB=6 and AB, then the number of elements in AB is equal to
MEDIUM
A survey shows that 63% of the people in a city read newspaper A whereas 76% read news paper B. If  x% of the people read both the newspapers, then a possible value of x can be:
HARD
In a certain town, 25% families own a phone,15% families own a car, 65% families own neither a phone nor a car and 2000 families own both a car and a phone. Consider the following Statements (S):
S1: 35% families own at least one of a car or a phone.
S2: 40,000 families live in the town.
Then:
HARD
For any three sets A, B and C the set (ABC)AB'C''C' is equal to
HARD
Let A=θR:13sinθ+23cosθ2=13sin2θ+23cos2θ. Then
EASY
If U is the universal set with 100 elements; A and B are two sets such that nA=50, nB=60 nAB=20 then nA'B'=
MEDIUM
Two newspapers A and B are published in a city. It is known that 25% of the city population reads A and 20% reads B while 8% reads both A and B. Further, 30% of those who read A but not B look into advertisements and 40% of those who read B but not A also look into advertisements, while 50% of those who read both A and B look into advertisements. Then the percentage of the population who look into advertisements is:
MEDIUM
In a certain town, 25% of the families own a phone and 15% own a car; 65% families own neither a phone nor a car and 2000 families own both a car and a phone. Consider the following three statements:

i 5% families own both a car and a phone.

ii 35% families own either a car or a phone.

iii 40000 families live in the town.

Then,